One evening I located a support group on the internet for people who were going to lose or had lost a loved one. Groping to make sense of my mother's suffering I told the group of my mother's death. They shared their experiences with me. I can't tell you why or when my healing began but only that hearing others' stories did this for me.
I came to believe that my mother's sudden fight to live was a defense mechanism that we all are programmed to have. We are programmed to survive. If you throw a person who can not swim into a pool they struggle to stay afloat. If you put a pillow over a person's head they struggle to take it off. Even if the person was terminally ill they would struggle. So even though my mother was ready to die, she struggled in the end. It was her last ditch effort to survive.